1. Field of the Invention
The invention relates to a closure means for a roof ventilator and, more particularly, to a frame-work and sliding door assembly for selectively closing roof ventilation openings.
2. History of the Prior Art
Many buildings include means for ventilating the air space within an attic to the outside atmosphere in order to dissipate moisture contained in the air within the attic, as well as to dissipate heat trapped in the attic space during hot weather. Such ventilation means may include a louvered window-like opening in the gable portion of the roof or at the end of the roof as well as conventional wind-driven turbine type ventilators which are mounted on the roof. Turbine type generators are rotated by the wind and serve to withdraw by turbine effect stagnant air from within the attic space and discharge it into the atmosphere. Fresh air from the outside then moves in through the louvered windows in the gables to replace the air in the attic space with fresh, cooler air.
Wind-turbine type roof ventilators are very effective in the cooling of a home during the summer months by removing the hot air which collects in the attic space beneath the surface of the roof. However, during the winter months, attic ventilators are not needed to discharge warm, stagnant air within the attic and, moreover, such ventilation contributes to a tremendous amount of heat loss from the attic space. This makes it much more difficult to efficiently warm the home during the winter months. Thus, it is desirable to close both wind turbine type vents as well as louvered window vents during winter months in order to maximize the efficiency of heating of a building.
A further problem associated with attic ventilation is that insects, such as wasps, as well as animals such as squirrels, chipmunks, and even domestic animals such as cats, may find entry into the attic of a building through either the louvered ventilation windows or by means of the interstices between adjacent blades of a turbine ventilator. Once an animal has received access to the attic it may cause damage to the insulation or wiring in the attic or be unable to escape from the attic and die there creating an olfactory nuisance for the occupants. In addition, the running and thrashing about of animals within an attic space can also be very disturbing to the occupants of a dwelling. Needless to say, the presence of wasps and other undesirable insects in the attic make it difficult to use the space for storage or other useful domestic purposes.
It has been recognized that it is desirable to close the ventilation openings of a wind turbine type attic ventilator during the winter months to conserve heat loss. In particular, U.S. Pat. No. 4,374,534 discloses a bag-like cover for encapsulating the entire turbine in order to reduce the heat loss from the turbine when ventilation is not required. Similarly, U.S. Pat. No. 4,231,288 discloses a disk-like closure member which is spring biased against the inside opening of a wind turbine beneath the roof in order to seal that opening during the cold months of the year and prevent heat loss from the dwelling through the opening. In addition, other patents such as U.S. Pat. No. 4,123,001, have taught damper, either operated by either temperature or pressure or both, located within the interior of the turbine ventilator in order to automatically vary the opening of the ventilator depending on environmental conditions.
Use of an exterior turbine cover requires that someone climb onto the outside of the roof in order to apply the cover which is often a dangerous operation. The disk-like seal is relatively cumbersome to apply since it is not an integral unit and must also be removed and put away during the warm months rather than being a permanent fixture to be installed at the time the turbine is installed. Moreover, none of these prior art devices also serve to prevent the entry of animals or insects and prevent their nesting within the attic of the building while at the same time provide for the selective closing of the opening beneath the ventilator as seasonally required.
The assembly of the present invention is a unitary structure which overcomes the disadvantages of the prior art by providing in a single assembly a means for preventing the entry and egress of animals and insects through the ventilation openings, while at the same time allowing the selective opening and closure of the ventilation means as required by the seasons.